I don't think the problem is, as much, the aluminum lug as it is the steel set screw they use in most that were designed for dry location use. The PoCo uses aluminum crimp sleeves all the time outside. I still believe you should be using a copper or bronze lug on pool equipment. The problem is, 680.26(B) simply refers you to 250.8 for the lug so you can't say there is any special "pool" type. You can only look for a listing that says wet location. If the installer can reasonably assert the equipment is in a dry location you don't even have that.
